<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>5×5</title>
</head>
<body style="width: 80%;margin: 0 auto">
<table>
    <tr>
        <td></td>
        <td></td>
        <td></td>
        <td></td>
        <td></td>
    </tr>
    <tr>
        <td></td>
        <td></td>
        <td></td>
        <td></td>
        <td></td>
    </tr>
    <tr>
        <td></td>
        <td></td>
        <td></td>
        <td></td>
        <td></td>
    </tr>
    <tr>
        <td></td>
        <td></td>
        <td></td>
        <td></td>
        <td></td>
    </tr>
    <tr>
        <td></td>
        <td></td>
        <td></td>
        <td></td>
        <td></td>
    </tr>
</table>
</body>
</html>

<style>
    table {
        border: 1px solid gray;
        text-align: center;
    }

    table tr {
        border: 1px solid gray;
        text-align: center;
    }

    table td {
        border: 1px solid gray;
        text-align: center;
        width: 80px;
        height:80px;
    }
</style>